/*
 * Copyright (c) 2010-2011, okazoh_tk. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 *  - Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *  - Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *  - Neither the name of the copyright holder nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include "alkes/graph/Updater.h"

namespace alkes {

Updater::Updater()
: context_(0)
{
}

Updater::~Updater()
{
}

void Updater::traverse(Composite* root)
{
    memset(bits_array_, 0, sizeof(bits_array_));
    Visitor::traverse(root);
}

void Updater::setUpdateContext(UpdateContext* context)
{
    context_ = context;
}

void Updater::visit(Visual& element)
{
    bool dirty_child = element.update(*context_);
    if (dirty_child) {
        uint32_t depth = getDepth();
        bits_array_[depth >> 5] |= 1 << (depth & 0x1F);
    }
}

void Updater::visit(Composite& element)
{
    if (!element.preUpdate(*context_)) {
        // Don't traverse children.
        skipChild();
        return ;
    }

    if (element.getLastChild()) {
        uint32_t depth = getDepth() + 1;
        bits_array_[depth >> 5] &= ~(1 << (depth & 0x1F));
    }
}

void Updater::visitPost(Composite& element)
{
    uint32_t depth = getDepth();

    bool dirty_child = element.postUpdate(*context_,
        0 != (bits_array_[depth >> 5] & (1 << (depth & 0x1F))));

    if (dirty_child) {
        --depth;
        bits_array_[depth >> 5] |= 1 << (depth & 0x1F);
    }
}

}
